Camelot extended his unbeaten record as he won on testing ground in the Irish Derby at the Curragh.

Aiden O'Brien's colt added the Irish crown to his Epsom Derby victory, while O'Brien won the Classic race for a seventh successive year.

There had been fears that Camelot may be pulled from the race with the going soft to heavy, but despite stablemate Imperial Monarch being declared a non-runner, Camelot stood his ground as one of five runners in the one mile four furlong contest.

In tough conditions, Camelot was given a scare by Born To Sea when Johnny Murtagh made his move a furlong out, but the unbeaten three-year-old was too strong as he claimed victory by three lengths.

"We were very worried about the ground," trainer O'Brien said. "At home he doesn't even walk on that ground. He was tested in every way today so I can't tell you how delighted we are."

Jockey Joseph O'Brien added: "He hated the ground all the way and I was worried turning in that he was struggling. He has a big heart."

Camelot remains on course for an historic treble - the St Ledger Stakes in September standing between him and the Triple Crown following his English 2000 Guineas and Epsom Derby wins.

However, there was no double celebration for O'Brien as Cristoforo Colombo was beaten by Probably in the Railway Stakes.